The present invention relates to a card adapter according to the preamble of claim 1. The invention also relates to a method according to the preamble of claim 10 for placing and connecting an expansion card to an electronic device. The invention also relates to a card-like wireless communication device according to the preamble of claim 12.
According to prior art, various electronic devices, such as portable personal computers (PC), PDA devices (Personal Digital Assistant), and also cameras are often equipped with an expansion card interface, to which a standardized expansion card can be connected. The interfaces are typically slot-like recesses extending inside the device, into which recesses the card is pushed, the card being typically fully accommodated therein. These expansion cards are intended to form a functional unit with the PC. The expansion cards may also contain radio parts of a wireless communication device including an antenna, wherein the PC can, by means of this card-like wireless communication device, communicate with other devices or with a communication network, e.g. the GSM network (Global System for Mobile Communication). The antennas placed in the cards are used for the transmission and reception of radio-frequency signals, and the signals are transmitted between the radio part and the antenna of the wireless communication device typically by means of conductors and connectors.
One known expansion card is the PC card according to the PCMCIA standard (Personal Computer Memory Card International Association). The PC cards are adapted to be fully inserted in the PC, but so-called extended PC cards are longer than ordinary PC cards. These extended PC cards are partly placed outside the PC, wherein the thickness and design of the PC cards can vary in this part to be placed outside the PC. In a way known per se, this part also accommodates the separate antenna for the wireless communication device.
One known card-like wireless communication device which comprises a transceiver with its antenna is the Nokia Cellular Card Phone, i.e. a card phone that can be connected to expansion card interfaces of types II and III of the PC card complying with the PCMCIA standard. One embodiment of the card phone of prior art is shown in FIG. 1, and the operation of the card phone is described in more detail e.g. in patent publication U.S. Pat. No. 5,809,115. In the card phone, the antenna part comprising the antenna is placed outermost in the part located outside the PC device, this part being connected to the card-like part of the card phone that is placed at least partly inside the expansion card interface. Other known card-like wireless communication devices are disclosed in patent publication U.S. Pat. No. 5,628,055, wherein a separate turnable antenna can be connected to the end of the card, and in U.S. Pat. No. 5,361,061, wherein a foldable antenna is pivoted at the end of the extended card on its upper surface.
Other known expansion cards include e.g. a so-called CompactFlash (CF) card complying with the CFA standard (Compact Flash Association). For example for these CF cards, there are also adapters of the size of the PCMCIA card, in which the CF card is placed in a detachable manner for the PCMCIA interface. By means of said adapters it is possible to connect a card of a different size, complying with another card standard to a expansion card interface equipped for a card standard of a particular size. In the most straightforward case, the adapter is provided with first connector means which are compatible with the connector means of the expansion card interface, and second connector means which are compatible with the expansion card to be adapted. In addition to this, the adapter is equipped with conductor means for connecting the connector means electrically to each other to transmit signals between the connector means. In some adapters there are also electric components, such as IC circuits fixed on a circuit board, by means of which the internal function of the card can be arranged to correspond to the function of the expansion card interface. When the card adapter and the expansion card, for example a card complying with the CFA standard, are connected together, they constitute a card-like structure complying, at least with respect of its physical dimensions, with a standard, e.g. the PCMCIA standard, and comprising connector means of the correct type.
Also known are expansion cards for a wireless local area network (WLAN), and other expansion cards also include a so-called Miniature Card, whose size is only 38 mmxc3x9733 mmxc3x973.5 mm, as well as a so-called SmartMedia card, whose size is only 45 mmxc3x9737 mmxc3x970.76 mm, and an MMC card (so-called MultiMediaCard), whose size is only 32 mmxc3x9724 mmxc3x971.4 mm.
One drawback in known card-like communication devices is the fact that during the use, being placed in an expansion card interface, particularly the antenna structure constitutes a part that protrudes from both the electronic device, the interface and the card. The interfaces often comprise a shielding cover for protecting the expansion card and the interface, which shielding cover has to be kept open when the antenna structure extends outside the electronic device. The protruding parts of the antenna structure and the card may stick in something particularly during the transportation and use of the device and may damage the card. For this reason, the card must be detached after the use and be stored separately from the device.
When the antenna structure is arranged in the card in such a way that the card fits fully inside the expansion card interface, there is a problem that the metal structures of the electronic device surrounding the card and said shielding cover considerably restrict the operating range of the card-like wireless communication device, especially the antenna, by interfering with the signal to be received and transmitted. The shielding cover may have been treated with metal paint or made of electrically conductive material, such as carbon fibre, which facts furher increase the interference and prevent the transmission of signals.
It is a purpose of the present invention to eliminate the aforementioned drawbacks by means of a card adapter according to the invention. The card adapter according to the invention is characterized in what will be presented in the characterizing part of claim 1. The method according to the invention is characterized in what will be presented in the characterizing part of claim 10. The card-like wireless communication device according to the invention is characterized in what will be presented in the characterizing part of claim 12.
It is an essential principle of the invention to allow the motion of the adapted expansion card, especially the wireless communication device, in the card adapter, so that the card can be moved in different functional positions. In the different positions, the electric contact to the card adapter as well as the connection to the electronic device are, however, retained to maintain operation. Thus, the central principle is that the aforementioned second connector means move along with the card in the adapter, and the conductor means are arranged to allow said motion.
The wireless communication device according to the invention does not have to be removed from the PC device for the time of transportation. Thus, the implementation of the PC device, the set-up of a radio connection, as well as the initialization of the wireless data transmission are expedited. At the same time the number of acts of attaching the card to the interface and detaching it from the interface is reduced, wherein the wearing of the connector means as well as failures are reduced. The card adapter according to the invention with its card constitutes an assembly, preferably with standard dimensions.
By means of the expansion card and the card adapter it is possible to produce an assembly which constitutes a card-like wireless communication device which can be supplemented in the presented simple way with a feature by means of which the antenna placed in the card can be moved in different positions. Thus, it is obvious that if the assembly is normally intented to be used as a unit, it is also possible to provide the card adapter with components necessary for the function of the wireless communication device. It is also possible to consider placing only the antenna of the wireless communication device on the card. The card adapter can also form an assembly together with the electronic device, by means of which assembly the card, especially a card-like wireless communication device with its antenna, can be movably connected to the device.
In some cases the operating range of the antenna and the card can be sufficient even though the card in its first functional position were located fully inside the interface, but by means of the invention, the card, and especially its antenna, can be moved outward from the interface into its functional position, which in many situations can be sufficient for a reliable reception of even a weak signal and for attaining a sufficient operating range. For transport, the card can be moved inward into the interface. A special advantage of the invention is that in the protruding functional position of the card, the antenna can be located in a free space outside the device. Thus, the antenna is located further off the components of the device, such as the processor of a computer, that cause radio interference. The effect of the electromagnetic interference caused by the components is reduced when the distance grows.
In expansion cards which are fitted in the adapter, the antenna can be located for example inside the card, or it can be integrated in the structures of the card, especially on the outer surfaces or in a part which is located outside the expansion card interface when the card is moved into different positions. The invention is applicable to be used especially in electronic devices suitable for low power radio frequency networks (LPRF) which can be used in wireless local area networks, such as piconets, wherein the operating distance is typically 0.1 to 10 m, even 100 m, if necessary. These wireless networks operate in the ISM range at the frequency of 2.4 GHz. The invention is suitable to be used in so-called Bluetooth technology, by means of which it is possible to replace cables with a radio channel e.g. between PC devices and peripheral devices.